Coil assembly for a solenoid valve

Abstract

A coil assembly for a solenoid valve includes a sealing member having a sealed cavity that generally encircles an opening containing an electrical lead extending from the windings of the coil. The sealing member is disposed within a encapsulating material that is pressure molded around the windings of the coil assembly. During the pressure molding process, the pressure from the molding process exerts a force on the outermost side of the sealing member and compresses the outer member. The force being exerted to the outermost diameter is transferred through the sealed cavity to the innermost portion of the sealing member forcing it into a forced intimate contact with the lead. The force on the lead is maintained after the pressure from the molding process is removed. This arrangement provides a seal between the lead and the sealing member that is effective to prohibit damaging elements reaching the windings contained in the coil assembly.

I claim: 
     
       1. A coil assembly, comprising: a bobbin having a cylindrical portion with flanges disposed at opposite ends thereof and an opening defined therethrough;   an electrical conducting winding disposed around the cylindrical portion of the bobbin with an electrical lead extending outwardly therefrom;   a sealing member having a sealed cavity defined therein and being disposed around the electrical lead; and   an encapsulating material pressure molded around the windings and encircling the electrical lead extending therefrom.   
     
     
       2. The coil assembly of claim 1 wherein the sealing member has a longitudinal length and an opening is defined therethrough along its longitudinal length and the inner surface of the opening is in intimate forced contact with the electrical lead. 
     
     
       3. The coil assembly of claim 2 wherein the sealed cavity generally encircles the opening of the sealing member along its longitudinal length. 
     
     
       4. The coil assembly of claim 3 wherein the opening has an undulating surface and the undulating surface is in intimate contact around the electrical lead at interrupted locations along its longitudinal length. 
     
     
       5. The coil assembly of claim 4 wherein the sealing member has an outermost diameter. 
     
     
       6. The coil assembly of claim 5 wherein the coil assembly has a second lead extending from the winding and includes a second sealing member having an opening defined therein with a sealed cavity generally encircling the opening therealong. 
     
     
       7. The coil assembly of claim 6 wherein the sealing members are made of an elastomeric material and the one end of each of the sealing members is disposed generally adjacent the outermost side of the encapsulating material. 
     
     
       8. The coil assembly of claim 5 wherein the outermost diameter is smaller at one end and the sealing member tapers from the one end to the other end. 
     
     
       9. The coil assembly of claim 5 wherein the other end of the hollow sealing member has an enlarged flange. 
     
     
       10. The coil assembly of claim 3 wherein the coil assembly has a second lead extending from the winding and the sealing member has a second opening defined therein with the sealed cavity defined therein generally encircling both of the first and second openings and the second lead extends through the second opening. 
     
     
       11. The coil assembly of claim 3 wherein the lead has an insulated covering and a sealant is disposed between the insulated covering and the lead.